This invention relates to a device for electrically measuring the amount of movement of a moving object including a rotating object and a linearly moving object.
For instance, the amount of rotation of a rotating object can be, in general, detected by a method in which the rotating object is graduated in equal spaces, and the amount of rotation of the rotating object is obtained by reading the graduations. In another method, the confronting surfaces of a rotating object and a stationary member have gear-like cuts as graduations, so that as the protrusions of the gear-like cuts are moved close to and away from one another with the rotation of the rotating object the capacitance of a capacitor formed thereby is changed, and the variation of the capacitance is detected to measure the amount of movement.
In the case where the amount of rotation should be read with high precision, it is assumed that the reading is effected by the second, i.e., by the unit of 1/3600 of one degree. Then, the periphery of the rotating object must be graduated by dividing it into 1,296,000=360.times.60.times.60.
However, such division is practically impossible. Accordingly, a device for measuring the amount of movement with high accuracy has not been proposed heretofore.